Line impression equalizer



Oct. 18, 1932.

E. L. SANDERS 1,882,955

LINE IMPRESSION EQUALIZER Filed Nov. 7, 1931 7 17 717 v w by i 12 .hWdILZZ/f 77i7/ze555a- Z241 Ma's 427:; 5?? I" Patented Oct. 18, 1932 UNITED STATES.

PATENT oFFiicE LQUIS sa DERs, (IF-CHICAGO, IL INOIS, AssIGNoR or ONE-HALF TQ warren J.

" SANDERS, F CHICAGO, ILLINOIS LINE IMPRESSION EQU-AIiIZER Application filed November. 7, 1831. Serial No. 573,101. 1

' for regulating the pressure of the presser element or platen so as to secure equalized impressions of relatively short lines with relation to. the longer lines of printing whereby to attain a higher degree of uniformity and neatness in the work produced. Other objects and advantages to be attained will hereinafter more fully' appear.

In printing machines ofthe character above noted, and particularly of the; kind' commonly known as a multigraph, in which the printing cylinder or segment is provided with a plurality of longitudinally extending circumferential grooves whose side walls are undercut to afford key slots and the individual type members or slugs, or other printing elements, are formed with counterpart portions to slidably fit. in said grooves rather tightly so as, to remain in their respective positions by frictional engagement, but usually more securely retained in set position by spring clip devices which are applied at the opposite ends of each line oftype or printing elements. 7 y

In practice, the sheet of paper to be printed is passed between the platen or presser roller andthe type or printing elements carried on the printing cylinder, each line of printing being impressed upon the paper as the rows of type or printing elements succes sively move into engagement. with the presser roller or platen, the type or printing elements being inked by moving into engagement with an inking roller prior to being acted upon by the presser roller or platen, or, in other cases, by a ribbon which is carried on the printing cylinder or segment and interposed between the type faces and the paper to. be printed. The adjustment of the presser roller or platen, with respect to the type carrying cylinder orsegment, is varied according to the thickness of the sheet of paper. to be printed and the consistency of the ink or density of the ribbon used, and, obviously, the pressure of the presser roller or; platen upon the type. carrying cylinder or segment is, constant, throughout the length thereof, and the same pressure is distributed upon the several lines; of type or printing. elements regardless of their respective lengths, so that theprinting of; a relatively short line appears heavier and appreciably darker than 'the longer lines. To overcome this effect devices have been applied to the type carrying cylin-v der or. segment in correlation to the respective relatively short lines of type or printing elements so, as, to bear some of the pressure. and

' relieve the line of type ofthe preponderance of pressure which would otherwise be'imposed thereon, and thereby secure more 1111i. formity in the printing throughout the entire body of the work on the sheet. These devices as applied equalize the impressions to some extent, but, owing to their structural characteristics and manner of application, cannot, in many cases, be applied where several relatively short lines occur in close succession,.and, furthermore, some of theequalizing devices comprise an elongated spring tongue which is disposedin longitudinal alignment with the relatively short line of type, and hasto. be laid over the ribbon, or, in other. words, disposed so as to. ride between the ribbon and the sheet of paper to, be printed, thus causing a clamping action intermittently upon the ribbon which interferes with the usual intermittent feeding travel of the ribbon, resulting in the mutilation of the ribbon in some cases, while in others the mutilation of the sheet being printed and also the surface of the presser roller or platen.

The present invention consists in the novel device and the method-of its application for equalizing line pressure of machines of the character above described, and for overcoming the disadvantages noted, as hereinafter described and pointed out with particularity in the appended claims.

In the accompanying drawing illustrating a practical adaptation of the invention Fig-1 is a fragmentary face View of aporv tion of the printing cylinder or segment and adjacent side plate of an ordinary printing machine of the kind herein described, showing the line impression equalizer applied in correlation to a relatively short line of printing type, together with the relatively positioned inking ribbon and sheet to be printed, the parts being shown on a somewhat enlarged scale to more clearly show the de-v tails of structure which are diflicultto illustrate in natural size;

Fig. 2 is a longitudinal section of the above noted parts, together with a cooperating portion of the presser roller or platen;

Fig. 3 is a section taken on or about the lines 33 of Figs. 1 and 2; and

Fig. 4 is a perspective view of the line impression equalizing device detached. Referring now to the drawing, the numeral 5 designates the type carrying cylinder or segment of a printing machine which is provided with a multiplicity of longitudinally disposed circumferential slots or slideways 6, the side walls of which are undercut, as at 7, to receive'therein the counterpart portions 8 of type elements or slugs 9. The cylinder or segment 5 is rotated about its longitudinal axis with its end closely adjacent to a stationary supporting plate 10 in which, in the usual machine structure, the cylinder or segment 5, or its carrier, is journalled, said plate 10 having a longitudinal circumferential slot or channel 11 through which respective type elements or slugs 9 are passed into the respective circumferential grooves or slideways 6 of the cylinder or segment 5 when said grooves are respectively brought into longitudinal alignment with said slot or channel 11. Also journalled in the supporting frame or plate 10 is a pressure roller or platen 12, said presser roller or platen and the cylinder or segment 5 being journalled at their opposite ends in another plate (not shown) similar to said sup porting plate or frame member 10.

As the particular means of operating the cylinder or segment 5 and the cooperating presser roller or platen 12, and also the means for adjusting the presser roller or platen with respect to the type carrying cylinder or segment 5, do not of themselves form any part of the present invention except as incidently cooperate directly in carrying out the present invention, it is deemed unnecessary to illustrate the particular details thereof in the accompanying drawing. In machines of this character the impression faces of the type or printing elements are inked through one of two methods, one of which is to locate an inking roller at some convenient position relative to the type carrying cylinder or segment 5 so that the several lines of type or printing elements are successively passed in engagement therewith, while another method of inking the type of printing elements is to provide the cylinder or segment 5 with a ribbon which and 3, and in section in Fig. 2 of the drawing.

In practice,' tl1e lines of type or printing ele- 'ments set up in the respective slots of slideways 6 of the cylinder or segment 5, are re tamed agalnst longitudinal movement 1n the slots, or .slideways by spring clip devices 15 which are forced into the grooves at opposite ends of the lines, said devices 15 having tongue portions 16 which overlap the endm'ost blank slugs 17 usually placed at the beginning and end of each line.

The impression equalizing device of the present invention comprises a slug 18 whichis somewhat elongated, said slug having a portion substantially T-shaped in cross-section, as at 19, and formed as an exact counterpart of the undercut slots or slideways 6 of the type carrying cylinder or segment 5, and fitting the latter rather snugly so as to remain in place unless appreciable force is applied to move the device. While the device, under ordinary use of the machine, may remain in its proper working position due to the comparatively tight fitting thereof to the slot orslideways 6, provision is preferably made for the application thereto of one of the spring clip devices 15 that are used for the retention of lines of type inthe composition of the matter to be printed. As shown, the upper inner end portion of the impression equalizing slug 18 is cut away as at 20 for the reception of the tongue'portion 16 of the spring clip 15 so as to leave the top face of the slug clear and free of any interfering protruberance. As above noted, there is little liability of the slug 18 moving endwise during the operation of the machine, and its outward movement being prevented by the abutting face of the supporting plate or frame member 10 except where the slot or channel 11 occurs, and the possibility of the slug entering said slot or channel 11 during the rotation of the cylinder or segment 5 being but slight, it is preferable to bevel the outer end of the slug, as at 21, so as to afford a cam surface which will engage the forward side of-theslot and cause the slug to move back to place should it start to move outwardly into the slot or channel during the rotation of the cylinder or segment 5; r

The impression equalizing slug leis proportioned so that its top face is slightly higher than the impression faces of the type or printing elements'in the line to which it is cooperatively applied. 'That is to say, the top face of the slug 18 is a minute fraction of an inch'higher than the face of the type so that when the correlated line of type to which the slug 18 is applied is brought into printing engagement with the presser roller or platen, the preponderance of pressure is upon the slug 18 which tends to correspondingly spring the presser roller or platen 12 owing to the characteristic composition of the material of which it is made, and thereby relieves the relatively short line of type of pressure in excess of that which would be imposed proportionately the length thereof if it was included in the relatively longer line of type.

In practice, the slugs 18 will be made of different sizes, as to height, because the rela tive height of the slug must, for practical purposes, be varied according to the differences in the lengths of the lines to which they are applied. That is to say, the shorter the line, the higher the slug, although the difference in dimensions is very minute and figured in thousanths of an inch.

The impression equalizing device of the present invention, according to the better practice, is preferably applied to the cylinder or segment 5 at the end thereof where the right-hand margin of the regular standard or ordinary printed sheet travels, and, of course, outside of the path of the inking ribbon 13 or the printing range of the type or printing elements and also beyond the marginal portion of the printed sheet of paper 14. However, in some cases, the equalizing slug 18 may be in the path of the marginal portion of the printed sheet and come in contact therewith, the effect being the same except that in such cases the slug 18 will, of course, be decreased in height to compensate for the thickness of the sheet of paper which is interposed between the slug and the platen.

While the construction and arrangement of the device and its application to the printing machine in the accompanying drawing illustrates a practical adaptation of the invention, it is to be understood that the same admits of considerable modification without departing from the spirit and scope of the invention as defined by the appended claims. The invention, therefore, is not limited to the precise construction and arrangement shown.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is:

1. In a printing machine of the character described and comprising a rotary printing element carrier having longitudinally disposed circumferential grooves for the reception of the respective lines of printing elements, an abutment member adjacent the end of said rotary carrier in opposed relation to the ends of the respective circumferential grooves of the carrier, a cooperating roller platen for effecting an impression of the printing elements upon a sheet passed therebetween, and a line impression equalizing device comprising an element insertable in a printing element receiving groove of said carrier in correlation to the line of printing elements therein, the circumferential face of said equalizing element being higher than the printing face of the correlated line of printing elements and the outer end of said equalizing element being beveled to slidably engage said abutment member with cam efi'ect.

2. The herein described line impression equalizing device comprising a slug insertable in the circumferential printing element receiving groove of a rotary printing element carrier, the outer end portion of said equalizing element being formed as a cam surface.

3. The herein described line impression equalizing device comprising a slug inserta-' ble in the circumferential printing element receiving groove of a rotary printing element carrier, the outer end portion of said equalizing element being beveled.

1. The combination of a rotary printing element carrier having longitudinally disposed circumferential printing element receiving grooves, a stationary abutment plate adjacent the end of said rotary carrier, said abutment plate having a circumferential channel therein for the successive registration therewith of the grooves of the circumferential printing element receiving grooves of said rotary carrier, and a line impression equalizing element comprising a slug insertable through the circumferential channel of said abutment plate into a circumferential printing element receiving groove of said carrier, the end portion of said equalizing element being formed with a cam surface engageable with said abutment plate to prevent said impression equalizing element from accidental outward displacement in the circumferential groove of said printing element carrier during the rotation thereof.

In testimony whereof I have signed my name to this specification.

EDGAR LOUIS SANDERS. 

